United says the bunny was alive when he was taken out of the cargo section of the plane in Chicago, but he passed away in a kennel facility at the airport.

Owner Annette Edwards, 65, says she now will never know how he died.

According to The Sun, she said: "I had been asking United over and over again for his body so that I can have him examined here in Britain but they never got back to me. All I want to know is how he died.

"He was fit as a fiddle when he left my house, and then 24 hours later he's dead."

The airline has denied allegations that Simon died after an airport worker mistakenly left him in a freezer overnight.

According to the NY Post, a spokesman said: "The assertion that Simon died in a freezer is completely false. Simon was cared for at the PetSafe kennel facility which is kept at room temperature (on average 70°F).